The invention relates generally to microwave applicators and systems for heat processing of dielectric materials.
Some dielectric bodies made by extruding plasticized deformable material using liquid as part of the plasticizing system may not have enough strength when wet to be self-supporting. To strengthen the extrudate, the extrusion process can be followed by a stiffening process, whereby the extrudate is heated to a selected temperature, for example, above a gelling point of a thermally-activated binder in the plasticizing system. Such a stiffening process is described in, for example, U.S. Pat. No. 5,223,188 issued to Brundage et al and U.S. Patent Application Publication No. US2006/0093209 by Bergman et al. In the Brundage et al patent and the Bergman et al publication, microwaves are used to heat the extrudate. Microwave heating is attractive for heating and stiffening dielectric bodies because microwaves can penetrate dielectric materials and provide heat to the interior of a volume.